The present invention relates generally to a fluid pressure actuated clutch and, more particularly, to a clutch of the type including a clutch plate having inner and outer pistons movable into engagement with a clutch pack to compress the pack and thereby engage the clutch. To move the pistons, a chamber located behind the pistons is filled with pressurized fluid. First and second spring means of different strengths urge the pistons rearwardly away from engagement with the clutch pack. Accordingly, when filling the chamber, one of the pistons slides forwardly with respect to the other and engages the clutch pack to partially compress the pack before the other piston engages it to complete engagement of the clutch. To disengage the clutch, the pressurized fluid is vented from the chamber and the first and second spring means urge the pistons out of engagement with the clutch pack.
A clutch of the foregoing type is disclosed in U.S. Pat. No. 3,612,237.